Not applicable.
Not applicable.
1. Field of the Invention
The present invention generally relates to portable computers. More particularly, the invention relates to connecting a portable computer to a drive wedge and a port replicator. Still more particularly, the present invention relates to docking and undocking a portable computer to a drive wedge and port replicator while the computer is powered on.
2. Background of the Invention
Portable computers, such as laptops, notebooks, sub-notebooks and the like, generally provide the performance and functionality of a desktop computer, but with advantage of portability. Smaller size and lower weight are achieved by making various design tradeoffs such as including a smaller size screen and keyboard in a portable computer versus a comparable desktop.
Some portable computer users desire to use a portable computer for extended periods of time. For example, for some it is desirable to use a portable computer at work and then bring the computer home for use at night. Because of the relatively small screen and keyboard sizes, some people find portable computers less than optimal for using in an office or home environment for extended periods of time, during which time portability is irrelevant.
To solve this problem, computer manufacturers offer various types of connection equipment that permit a portable computer to connect easily to various desktop peripheral devices. One type of connection device is a xe2x80x9cport replicatorxe2x80x9d which is an electronic device positionable on the desktop or other work surface. The replicator serves as an interface between the portable computer and the various desktop peripherals with which it is to be used. A port replicator typically includes a housing having a rear panel with various connectors accessible from the rear of the replicator. A series of interconnection cables connect the selected peripheral equipment to the connectors on the rear panel of the port replicator. The replicator also includes a front portion that has one or more connectors which matingly engage corresponding connector(s) on a rear panel of the portable computer when the computer is placed on the desktop and pushed against the port replicator. The connectors on the rear panel of the replicator are wired to the connector(s) on the front of the replicator to which the computer connects, thereby providing electrical connection between the portable computer and the various peripheral devices. A port replicator usually remains on the desktop connected to the various peripheral devices and the portable computer is connected to or disconnected from the replicator as the user desires, thereby avoiding the hassle of connecting various peripheral devices each time the portable computer is to be used with such devices.
At least one manufacturer also provides a drive xe2x80x9cwedgexe2x80x9d that contains one or more storage devices such as a CD ROM, DVD drive, floppy drive, CD read/write drives and LS-120 drive. A drive wedge offered by Compaq Computer Corp., for example, is a relatively flat device that engages the bottom surface of a Compaq portable computer by way of a single connector. The wedge includes another connector that permits the computer/wedge combination to mate to a port replicator. By providing various storage devices (e.g., floppy drive) in the detachable wedge, the portable need only contain a hard drive, and as such, is relatively thin and lightweight. Accordingly, when a floppy drive and CD ROM are not needed, the user is able to use a computer that is smaller and lighter weight than it would otherwise be with such peripheral devices.
The process of connecting the portable computer to a wedge and/or a port replicator is often referred to as xe2x80x9cdocking.xe2x80x9d The reverse process of disconnecting these components is called xe2x80x9cundocking.xe2x80x9d In conventional computer systems, docking and undocking required the computer to be completely off before docking or undocking. Thus, if the portable computer was already booted up and running, the user first had to turn the computer off, then dock it to the port replicator, and then reboot the computer. This order was necessary to ensure that the computer and its operating system knew what peripheral devices were available for use, information which was only obtained during the Power On Self Test (xe2x80x9cPOSTxe2x80x9d) process during boot up. More recently, with the advent of portable computers that implement the Advanced Configuration and Power Interface (xe2x80x9cACPIxe2x80x9d) or Advanced Power Management (xe2x80x9cAPMxe2x80x9d) standards which permit a computer to efficiently transition to a lower power mode of operation (commonly referred to as a xe2x80x9csleepxe2x80x9d mode), portables need not be completely shut down before docking or undocking. Instead, the computer could be transitioned to a xe2x80x9csleepxe2x80x9d mode and then docked or undocked. Sleep modes are lower power modes in which various subsystems in the computer are turned off to save power. Waking a computer from a sleep mode is a much faster process than cold booting the computer that was completely shut down, and thus docking/undocking a computer by putting the computer to sleep permits the computer to resume normal operation following the dock event much quicker. Upon resuming from sleep, the computer""s Basic Input Output System (xe2x80x9cBIOSxe2x80x9d) and operating system coordinate to re-detect attached peripheral devices.
It would be better still to be able to xe2x80x9chot dockxe2x80x9d a computer. Hot docking means docking or undocking a portable computer from a connection device, such as port replicator, while the computer is and remains fully operational. Hot docking thus would not require the portable computer from being turned off or even placed into a sleep mode. A computer that can be hot docked thus would further minimize the hassle experienced by some users of conventional computers.
The problems noted above are solved in large part by a portable computer that can be xe2x80x9chotxe2x80x9d docked to one or more expansion devices. As such, the expansion devices can be connected to and disconnected from the portable computer while portable computer is powered on and fully operational. The portable computer includes control logic that detects when an expansion device is connected or disconnected and asserts an interrupt to the computer""s CPU to initiate a sequence of events by which the computer determines whether an expansion device has been connected or disconnected. If the CPU determines that the expansion device has been connected to the computer, the CPU appropriately reconfigures itself to communicate with the expansion device. If the expansion device is disconnected, the CPU also appropriately reconfigures itself to preclude communications with the disconnected device.
In accordance with a preferred embodiment of the invention, the portable computer can be hot docked to a drive wedge (and hot un-docked therefrom) which may contain one or more storage devices. The portable computer/drive wedge combination, in turn, can be hot docked to a port replicator (and hot un-docked therefrom).
In accordance with a preferred embodiment, the port replicator contains an analog portion of a network interface and the portable computer contains the corresponding digital portion of the network interface. The full network interface capability, therefore, is not available unless the portable computer is docked to the port replicator. To prevent the digital network interface portion in the portable computer from attempting to operate without the analog portion being available and used when the portable is not docked to the port replicator, the configuration select input signal to the digital network interface portion is masked by a signal that indicates whether the port replicator is docked. Preferably, masking of the configuration select input signal is provided by an AND gate connected to the digital network interface portion.